Who is Pilar from By the River Piedra I Sat Down and Wept and what is their importance?

Pilar is the main character of the book. At first, she is a very closed-off person, who is obsessed with planning and trying to find love. She wants to marry a good man, have children, live in a nice house and have a good, stable life. She was born and raised in a small conservative town in Spain called Soria. She is a timid person, scared to branch out and learn new things because she fears change and rejection.